proper use

Not using condoms for all contact: could I be pregnant?

Sage
asks:
I have been sexually active for about 3 months now. Usually before sex, my partner and I have a few minutes of unprotected sex and then he puts a condom on. My period is now a week late and I'm worried. I already took a test that came out negative but I'm still kinda scared. My friend told me that it's usual for my period to not come when first having sex....